Pneumatic somatosensory stimulation device and method

ABSTRACT

A device for providing tactile stimulation of a subject via a pulse of compressible fluid, typically for medical diagnostic and therapeutic applications. The device preferably includes a high pressure fluid source and a low pressure fluid source. A pressure valve selectively connects the pressure sources to an outlet conduit. The outlet conduit includes an applicator for directing pulses against the skin of a subject. The pulses may be applied via one applicator or a plurality of applicators, and may be applied in one pattern or several patterns at various application sites. A method of providing tactile stimulation is also disclosed.

RELATED APPLICATION

The current patent application is a continuation patent applicationwhich claims priority benefit with regard to all common subject matterto identically-titled U.S. patent application Ser. No. 16/273,236, filedFeb. 12, 2019, which, itself, is a continuation patent application whichclaims priority benefit with regard to all common subject matter toidentically-titled U.S. patent application Ser. No. 14/537,718, filedNov. 10, 2014, which, itself, claims priority benefit with regard to allcommon subject matter to U.S. Provisional Application Ser. No.61/904,097, filed Nov. 14, 2013, entitled PNEUMATIC SOMATOSENSORYSTIMULATION DEVICE. The listed earlier-filed non-provisionalapplications and provisional application are hereby incorporated byreference in their entireties into the current patent application

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to apparatuses and methods for tactilestimulation. The present invention more particularly relates to apneumatic device and method for tactile stimulation using pulses ofcompressible fluid.

2. Discussion of the Prior Art

Tactile stimulation devices operate by inducing activation of the nerveendings and receptors proximate to a subject's skin, commonly either byapplying electrical voltage to, or by mechanically stimulating, thesurface of the skin. Once a neuron is activated, normal operationinvolves firing a signal along a neuronal path to the brain where thesensory input signal is ultimately interpreted, for example as asimulated puff or tap.

Tactile stimulation has a number of uses, primarily in the medicalfield, which include testing and diagnosis as well as therapeuticapplications. For example, it is common to correlate tactile stimuliwith brain activity to determine whether a neuronal path and/or thebrain are functioning properly, such as in stroke victims, and/or toprovide therapy using patterns of tactile stimulation. Where brainactivity is recorded in response to tactile stimuli, it is typicallydetected using functional magnetic resonance imaging (fMRI),magnetoencephalography scanning (MEG), or the like. Subjects' physicalresponses elicited by tactile stimulation devices, such as reflexivemovements, may also or alternatively be measured. Additional informationon somatosensory stimulation and its applications can be found in U.S.Publication No. 2012/0157895 A1 (Barlow et al.), which is herebyincorporated by reference in its entirety.

It is common to refer to a graph of stimulus levels (whether stimuluslevels are measured by amplitude in volts, pressure/force or otherunits) over time as a “waveform,” with such stimulus levels beingsusceptible of measurement at a variety of locations but most commonlyat an application site. Different pulse waveforms, for examplerectangles or parabolas, and frequencies are desirable for differentapplications and objectives.

Known tactile stimulation devices that rely on electrical current tocarry pulses that induce neuronal signal firing typically do so bydriving current to an application site where it is either applied to theskin directly via an electrode or the like, or where it is used toactuate a physical intermediary that translates the current intomechanical motion and contact with the subject. An example of the lattertype is a coil wrapped around a cylinder, where the current-bearing coilinteracts with an existing magnetic field to induce movement of thecylinder toward the skin of a subject. Electrical current tactilestimulation devices suffer from shortcomings which include thepossibility of interference with brain activity measurements anddiscomfort for the subjects, and difficulty attributing brain activitymeasurements to bodily responses rather than the stimulation device andits pulse(s).

Known tactile stimulation devices that rely on air as a pulse transfermedium typically comprise a compressor motor for supplying pulses of airto a line directed toward an application site of a subject. Such devicesare generally configured so that the compressor motor may be turned onand off to create pressurized pulses at a given frequency for deliveryalong the line to the application site. Stimulation by these devices mayeither be effected by direct expulsion of the air pulses onto thesubject's skin or other sensory surface (such as the throat) or by anair-actuated physical intermediary affixed to the skin, such as a simpleretractable cylinder, that directly translates at least some of theforce of the air pulses into mechanical contact with the skin.

Tactile stimulation devices relying on air for delivery of pulses to asubject suffer from a number of shortcomings, including sluggish pulserise time and imprecise waveforms. It is known to attempt to correct forthese shortcomings in applications where pulses travel over relativelylong tube passages such as ten to twenty feet by locating a chamberholding compressed air to supply the pulses closer to the applicationsite of the subject. However, such designs may involve increasedcomplexity and cost, and the undesirable placement of additionalequipment in “clean” rooms in which measurements are being taken. It istherefore desirable to provide an improved pneumatic device and methodfor tactile stimulation using pulses of compressible fluid.

This background discussion is intended to provide information related tothe present invention which is not necessarily prior art.

SUMMARY

Embodiments of the present invention solve the above-described and otherproblems and limitations by providing an improved tactile stimulationusing a pneumatic device for delivering pulses of compressible fluidover a distance so that sluggish rise time, imprecise waveforms andother disadvantages of existing pneumatic tactile stimulation devicescan be minimized. In one implementation, the present inventionaccomplishes this with a less complex and less expensive solution thatdoes not, for example, require positioning of pressure sources that arelikely to interfere with sensory equipment operation.

According to one aspect of the present invention, a tactile stimulationdevice includes a high pressure fluid source, a low pressure fluidsource, and an outlet conduit being fluidly connectable to the fluidsources and including an applicator configured to direct a pulse againstthe skin of a subject. The device further includes a pressure valvefluidly interposed between the applicator and the fluid sources. Thepressure valve is shiftable between a high pressure position, in whichthe high pressure fluid source is fluidly connected to the outletconduit, and a low pressure position, in which the low pressure fluidsource is fluidly connected to the outlet conduit. Positioning of thepressure valve in the high pressure position and the low pressureposition supplies the pulse of compressible fluid to the applicator.

A second aspect of the present invention concerns a device for providingtactile stimulation via a pulse of compressible fluid. The deviceincludes a pressurized fluid source operable to generate the pulse ofcompressible fluid, a vacuum pressure source, and an outlet conduitfluidly connectable to the sources and including an applicatorconfigured to direct the pulse against the skin of a subject. The devicefurther includes a vacuum valve shiftable between a vacuum position, inwhich the vacuum pressure source is fluidly connected to the outletconduit, and a pulse position, in which the vacuum pressure source isnot fluidly connected to the outlet conduit. The vacuum valve shiftingfrom the vacuum position to the pulse position permits the pulse ofcompressible fluid to propagate toward the applicator.

In regard to a third aspect of the present invention, a tactilestimulation method is provided. The method includes the steps ofsupplying a high pressure compressible fluid toward an applicator, and,after passage of a first predetermined amount of time, switching theflow of high pressure fluid to a flow of low pressure compressible fluidtoward the first applicator. According to this embodiment, the highpressure fluid flows for less time than the low pressure fluid togenerate the pulse of compressible fluid to the first applicator.

This summary is provided to introduce a selection of concepts in asimplified form. These concepts are further described below in thedetailed description of the preferred embodiments.

This summary is not intended to identify key features or essentialfeatures of the claimed subject matter, nor is it intended to be used tolimit the scope of the claimed subject matter.

Various other aspects and advantages of the present invention will beapparent from the following detailed description of the preferredembodiments and the accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Preferred embodiments of the present invention are described in detailbelow with reference to the attached drawing figures, wherein:

FIG. 1a is a front perspective view of a tactile stimulation deviceconstructed in accordance with a first preferred embodiment of thepresent invention together with a sensing device;

FIG. 1b is a front perspective view of the device of FIG. 1 a;

FIG. 1c is a front perspective view of the device of FIGS. 1a-b ,illustrating the control panel cover in a retracted condition;

FIG. 1d is a partially sectioned elevated side perspective view of thedevice, with the upper section of the housing being removed to show thetop compartment of the device of FIGS. 1a -c;

FIG. 2a is a front perspective view of the device of FIG. 1 withapplicators applied to the arm of a subject, and depicting part of theoutlet conduits associated with the applicators, with one of theconduits being shown connected to the control panel;

FIG. 2b is an enlarged cross-sectional side view of one of theapplicators;

FIG. 3a is a partially sectioned perspective of the device of FIGS. 1and 2, with the upper housing section and part of the lower housingsection being removed to show the vacuum outlet side of the bottomcompartment;

FIG. 3b is a partially sectioned perspective view of the device takenfrom the opposite angle of FIG. 3a to show the pressure outlet side ofthe bottom compartment;

FIG. 4a is a schematic flow diagram of the fluid components of thedevice of FIGS. 1-3, depicting the device with just one outlet conduit;

FIG. 4b is a schematic flow diagram of the fluid components of thedevice of FIGS. 1-4 a, depicting the device with three outlet conduits;

FIG. 5a is a partially sectioned perspective of the device of FIGS. 1-4,with the upper housing section and part of the lower housing sectionbeing removed to show the valve and control panel side of the bottomcompartment;

FIG. 5b is a partially sectioned perspective view of the device takenfrom the opposite angle of FIG. 5a to show the power supply side of thebottom compartment; and

FIG. 6 is a schematic flow diagram of the fluid components of a deviceconstructed in accordance with a second embodiment of the presentinvention, with the device having one outlet conduit.

The drawing figures do not limit the present invention to the specificembodiments disclosed and described herein. The drawings are notnecessarily to scale, emphasis instead being placed upon clearlyillustrating the principles of the preferred embodiments.

Furthermore, directional references (e.g., top, bottom, front, back, up,down, etc.) are used herein solely for the sake of convenience andshould be understood only in relation to each other. For instance, acomponent might in practice be oriented such that faces referred to as“top” and “bottom” are sideways, angled, inverted, etc. relative to thechosen frame of reference.

It is also noted that, as used herein, the terms axial, axially, andvariations thereof mean the defined element has at least somedirectional component along or parallel to the axis. These terms shouldnot be limited to mean that the element extends only or purely along orparallel to the axis. For example, the element may be oriented at aforty-five degree (45°) angle relative to the axis but, because theelement extends at least in part along the axis, it should still beconsidered axial. Similarly, the terms radial, radially, and variationsthereof shall be interpreted to mean the element has at least somedirectional component in the radial direction relative to the axis.

It is further noted that the term annular shall be interpreted to meanthat the referenced object extends around a central opening so as to begenerally toroidal or ring-shaped. It is not necessary for the object tobe circular, nor does the object have to be continuous. Similarly, theterm toroidal shall not be interpreted to mean that the object must becircular or continuous.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is susceptible of embodiment in many differentforms. While the drawings illustrate, and the specification describes,certain preferred embodiments of the invention, it is to be understoodthat such disclosure is by way of example only. There is no intent tolimit the principles of the present invention to the particulardisclosed embodiments.

In this description, references to “one embodiment”, “an embodiment”, or“embodiments” mean that the feature or features referred to are includedin at least one embodiment of the invention. Separate references to “oneembodiment”, “an embodiment”, or “embodiments” in this description donot necessarily refer to the same embodiment and are not mutuallyexclusive unless so stated. Specifically, a feature, structure, act,etc. described in one embodiment may also be included in otherembodiments, but is not necessarily included. Thus, particularimplementations of the present invention can include a variety ofcombinations and/or integrations of the embodiments described herein.

FIG. 1a illustrates a tactile stimulation device 10 and a genericsensing device 12 shown as a cylinder surrounding the head H of thesubject, which may be a human or other animal having somatosensoryreceptors. The sensing device 12 may be used in certain embodiments toprovide data to a computer 14 regarding the subject's reaction(s) to apulse supplied by the tactile stimulation device 10. In the preferredembodiment, the computer 14 is also part of a control system of thetactile stimulation device 10, as discussed in further detail below. Thesensing device 12 may include any of a variety of known equipment usedfor sensing neuronal activity in the brain or elsewhere in the nervoussystem of the body, such as fMRI or MEG equipment, and/or may include amechanical, auditory or optical sensing device such as a motion sensor,microphone or camera, without departing from the spirit of the presentinvention.

Broadly characterized, embodiments of the present invention provideimproved tactile stimulation using a pneumatic device for deliveringpulses of compressible fluid over a distance so that sluggish rise time,imprecise waveforms and other disadvantages of existing pneumatictactile stimulation devices can be minimized. In one implementation, thepresent invention accomplishes this with a less complex and lessexpensive solution that does not, for example, require positioning ofpressure sources that are likely to interfere with sensory equipmentoperation.

Referring to the figures, a tactile stimulation device 10 constructed inaccordance with a preferred embodiment of the present invention isshown. Referring to FIGS. 1a-d , the device 10 generally includes amobile housing 20 having a dome upper section 22 defining an uppercompartment 24 and an octagonal lower section 26 defining a lowercompartment 28 (see FIG. 3a ). The upper section 22 of the mobilehousing 20 includes an arcuate control panel cover 30 for retractablecovering of a control panel 32. The upper section 22 further includes arectangular rim 34 defining a panel opening 36. The control panel 32 isfixed to an inner surface (not shown) of the rectangular rim 34. Therectangular rim 34 of the upper section 22 further defines bearingsurfaces 38 along two sides of the panel opening 36 that receive thepanel cover 30 and along which the panel cover 30 can slide to reveal orconceal the control panel 32.

The upper and lower sections 22, 26 of the mobile housing 20 may beseparated by lifting the upper section 22 away from the lower 26. Inalternative embodiments, the sections 22, 26 may be releasably fixed toeach other by common releasable fasteners (not shown) such as clips orpins. An annular flange 40 (see FIG. 1d ) extends from a top portion ofthe lower section 26 of the mobile housing 20, and the upper and lowercompartments 24, 28 are separated by a substantially planar removableplatform 42 supported on the flange 40. The mobile housing 20 providessupporting and transportable structure for many of the device's 10components, while also providing reasonable access to such componentsfor maintenance and tuning. The shape and configuration of the mobilehousing 20 may be varied without departing from the principles of thepresent invention.

Turning now to FIGS. 1a-d and 2a , the device 10 preferably includes aplurality of outlet conduits 50. In the illustrated embodiment, theconduits 50 extend through the control panel 32 toward a subject.Preferably, the device includes a sleeve 52 for holding and directingthe outlet conduits 50 over part of their initial proximate length (seeFIG. 1a ). Each conduit 50 preferably terminates in a distal applicator54 affixed to the subject's skin. Each outlet conduit 50 includes anexternal section 50 a that is outside the mobile housing 20, and aninternal section 50 b located inside the mobile housing 20. Preferably,each conduit 50 also includes a quick coupler 50 c seated in the controlpanel 32. The quick coupler 50 c releasably receives the correspondingexternal section 50 a to establish fluid connection to the respectiveinternal section 50 b (see FIG. 1d ). Each internal section 50 b issecured to the internal side of the corresponding quick coupler 50 c.

Each external section 50 a preferably includes tube portions ofdifferent flexibility, with a portion of stiffer tube proximate to themobile housing 20 being joined to a distal portion of more flexible tubenearer the subject. The portions may be integral, or may be coupledusing common coupling structures (not shown) such as quick couplers ortubing clamps (i.e., perforated metal bands with screw fasteners).Another exemplary tube coupling structure may include a friction fitcoupling head formed at the end of the stiffer tube portion. Thecoupling head may be configured for insertion into the end of the moreflexible tube portion to complete the friction fit. It is envisionedthat other coupling structures for joining the portions of each externalsection 50 a may be used without departing from the spirit of thepresent invention.

During setup and operation, the stiffer tube portions of the externalsections 50 a may improve handling and positional retention of theexternal sections 50 a as they extend from the mobile housing 20 towarda space near the subject, and the more flexible tube portions mayprovide for easier adjustment of the applicators 54 in the space nearthe subject so they may be fixed in desired application site pattern(s).

In a preferred embodiment, the outlet conduit 50 comprises plastictubing such as urethane or silicone tubing or other materials havingminimal magnetic responsiveness, with a minimum inner passagewaycross-sectional dimension of between about 0.002 square inches and about0.05 square inches.

The outlet conduit 50 also is preferably of a smooth bore to minimizepressure drop of the compressible fluid along its length. The externalsections 50 a of the outlet conduits 50 are preferably between aboutthree (3) and about thirty (30) feet in length, and are about sixteen(16) feet in many commercial embodiments. However, it is envisioned thatoutlet conduits comprising different materials, dimensions andproperties may be utilized in other embodiments without departing fromthe spirit of the present invention. For example, it is not required tohave separate internal and external sections of the outlet conduitcoupled by a quick coupler. The outlet conduit may alternatively be onecontinuous tube. Likewise, it is not required that the part of theoutlet conduit that is outside the mobile housing comprise two portions,but could instead merely comprise one integral portion having uniformflexibility.

Turning now to FIG. 2b , an applicator 54 is illustrated at the distalend of each outlet conduit 50. The preferred applicator 54 is generallycylindrical, and includes an annular lip 54 a extending radially outwardfrom an interior space 54 b defined by an inner surface of an applicatorwall 54 c. The annular lip 54 a is configured to provide a sealingsurface generally facing the subject that may be affixed to thesubject's skin, for example using an adhesive or tape, to hold theapplicator 54 against the skin. The seal may or may not be substantiallycomplete, depending on the embodiment employed. The applicator 54further includes a base 54 d having an internal passage 54 e forcarrying pulses from the external section 50 a into an entry chamber 54f of the base 54 d. Pulses flowing from the external section 50 a firstflow through the base 54 d at its internal passage 54 e and then entrychamber 54 f, and exit the base 54 d into the interior space 54 b. Thepulses are then expelled onto the subject's skin to provide tactilestimuli.

The applicator 54 may, in alternative embodiments, include an applicatorattachment such as a vibratory membrane or retractable cylinder fortranslating the pulses of compressible fluid into mechanical movement ofthe applicator attachment toward and into contact with the skin of thesubject to achieve stimulation.

It is envisioned that the applicator may alternatively comprisedifferent shapes, dimensions and flow paths without departing from thespirit of the present invention. For example, it is not required to havea distinct structure for delivering pulses to the skin of the subject,and a generic terminal end of an outlet conduit may alternatively beoperable to fix against the subject's skin for delivery of pulses. Byway of further example, applicators may vary in shape and dimension,including with respect to internal flow passageways and the presence orabsence of internal chambers. An alternative applicator may furtherinclude rotatable or swiveling connections to tubing of the externalportion of the outlet conduit, without departing from the spirit of thepresent invention.

Turning to FIGS. 3a-b and 4a-b , the device of the preferred embodimentis illustrated further including a high pressure fluid source 60, lowpressure fluid source 62, and vacuum pressure source 64. In theillustrated preferred embodiment, high pressure fluid source 60 includesan upstream pressure supply 70 beginning at a compressor 72. Pressuresupply 70 includes a compressor pressure outlet 70 a (see FIG. 3b ) anda T-connection 70 b that includes a pressure release valve 70 c.T-connection 70 b also includes a needle valve 70 d for regulating theflow of compressible fluid to a low pressure feed line 76 a (seediscussion of low pressure fluid source 62 below). Pressure releasevalve 70 c is configured to open and release compressible fluid if thefluid pressure exceeds a threshold value, and to close once thecompressible fluid pressure recedes below the threshold value.T-connection 70 b is also fluidly connected to tube 78 a, and tube 78 asupplies compressible fluid to high pressure regulator 78 b which, inturn, is fluidly connected and supplies compressible fluid at a highpressure to high pressure regulator outlets 60 a. In a preferredembodiment, the high pressure regulator 78 b supplies compressible fluidto high pressure regulator outlets 60 a at between about six (6) psigand about ten (10) psig, and at about seven (7) psig for many commercialembodiments. High pressure regulator outlets 60 a are fluidly connectedto each other. High pressure regulator outlets 60 a are alsorespectively fluidly connected to a high pressure reservoir 60 b and ahigh pressure manifold inlet tube 60 c. High pressure fluid source 60further includes high pressure manifold 60 d, which is fluidly connectedto and supplied with compressible fluid by the high pressure manifoldinlet tube 60 c.

Low pressure fluid source 62 also includes upstream pressure supply 70beginning at compressor 72 and including outlet 70 a, t-connection 70 b,release valve 70 c and needle valve 70 d. Needle valve 70 d feeds line76 a. Line 76 a is fluidly connected to low pressure reservoir 62 dwhich, in turn, is fluidly connected via the components discussed belowto low pressure regulator 76 b. Low pressure regulator 76 b ispreferably a back pressure regulator, and is configured to releasecompressible fluid to the ambient environment to regulate thecompressible fluid and substantially maintain it at the low pressure.Compressible fluid at low pressure is supplied by the low pressureregulator 76 b to low pressure regulator outlet 62 a. Low pressureregulator outlet 62 a is fluidly connected by tube 62 b to T-connection62 c that fluidly connects low pressure reservoir 62 d and low pressuremanifold inlet tube 62 e. Low pressure fluid source 62 further includeslow pressure manifold 62 f, which is fluidly connected to and suppliedwith compressible fluid by the low pressure manifold inlet tube 62 e. Inthe illustrated preferred embodiment, the low pressure regulator 76 bsupplies compressible fluid to regulator outlet 62 a at between aboutone (1) psig and about two (2) psig, and at about one and on-half (1.5)psig for many commercial embodiments.

Employing a back pressure regulator in this embodiment is preferablebecause it facilitates regulation of pressure spikes experienced in thelow pressure fluid source 62 during operation of the device (seediscussion below) by venting compressible fluid. However, a variety ofregulators may alternatively be employed within the pressure sources, orno regulator(s) provided at all, without departing from the spirit ofthe present invention.

Returning to FIGS. 3a-b and 4a-b , vacuum pressure source 64 includesupstream vacuum supply 84. Vacuum supply 84 includes compressor 72,compressor outlet 84 a (See FIG. 3b ) and a T-connection 84 b having apressure release valve 84 c. T-connection 84 b fluidly connectscompressor outlet 84 a to tube 84 d (see FIG. 3a ). Tube 84 d suppliesvacuum to vacuum pressure regulator 84 e which, in turn, is fluidlyconnected and supplies vacuum at a vacuum pressure to vacuum pressureoutlet 64 a. In a preferred embodiment, the vacuum pressure regulator 84e supplies vacuum to vacuum pressure outlet 64 a at between aboutnegative one (−1) psig and negative two (−2) psig, and at about negativeone and one-half (−1.5) psig in many commercial embodiments. Vacuumpressure regulator outlet 64 a is fluidly connected by tube 64 b tot-connection 64 c that fluidly connects vacuum pressure reservoir 64 dand vacuum pressure manifold inlet tube 64 e. Vacuum pressure source 64further includes vacuum pressure manifold 64 f, which is fluidlyconnected to and supplied with vacuum pressure by the vacuum pressuremanifold inlet tube 64 e.

As perhaps best shown in FIGS. 5a-b , the compressor 72 preferablyprovides both the compressor pressure outlet 70 a and vacuum outlet 84a. In a preferred embodiment, the compressor 72 is a piston pumpoperated by an AC motor and is configured to supply compressor pressureoutlet 70 a with pressurized fluid at about ten (10) psig and the vacuumoutlet 84 a with a vacuum pressure at between about negative twelve(−12) psig and about negative thirteen (−13) psig. The compressor 72 ofthe preferred embodiment is configured to utilize ambient air as thecompressible fluid. However, it is foreseen that other compressiblefluids may be utilized in alternative embodiments according to anassessment of desirable fluid properties such as compressibility,specific heat, friction properties and others, without departing fromthe spirit of the present invention.

It should be noted that the objective of the components illustrated inthe preferred embodiment of FIGS. 3a-b and 4a-b is to supply threepressure sources using an efficient design so that each source may befluidly connected to each outlet conduit by actuation of one or two fastacting valves. In fact, the availability of at least two pressuresources is critical to the functioning of the preferred embodiment ofthe present invention. In the preferred embodiment, a high pressureburst is followed as closely as possible by the sustained low pressurecarrier wave.

FIGS. 3a-b and 4a-b do, however, merely illustrate a preferredembodiment, and a variety of components for generating, controlling anddirecting the flow of compressible fluid may be used without departingfrom the spirit of the present invention. Alternatively put, so long asat least two fluid pressure sources are supplied for selectiveapplication to an outlet conduit, various embodiments of the presentinvention may employ a variety of fluid components known to those ofordinary skill in the art as part of the pressure sources. For example,each manifold of the illustrated preferred embodiment includes acylindrical chamber (not shown) running beneath and fluidly connected toone set of valves (i.e., pressure valves or vacuum valves, as will bedescribed). However, it is envisioned that other pressure volumes andflow path intermediary components for separating flow to each conduitmay be utilized without departing from the spirit of the presentinvention.

Further, pressure sources may share a common supply, such as thecompressor of the preferred embodiment described herein, or mayalternatively draw from distinct respective supplies without departingfrom the spirit of the present invention. Still further, each supplyneed not comprise a compressor, but may alternatively be other supplyvolume(s) such as pressurized tanks or the like.

Pressure drop across components that are not primarily configured formanipulating fluid pressure—such as along tube lengths, across valves,and across components having different cross-sectional areas—is anatural consequence of fluid flow. It is anticipated that the preferredembodiment will minimize such natural pressure change(s) as fluid flowswithin each pressure source. However, appreciable pressure drop isexpected as pressure waves travel along an outlet conduit to anapplicator in many embodiments. Nonetheless, a single label is usedacross each flow path to refer to a pressure wave, regardless ofpossible natural pressure losses occurring along the way. Use of asingle label for a pressure wave at two or more points along a flowpath—such as referring to the supply of the “high pressure fluid” at theoutlet of the corresponding regulator and to the downstream supply ofthe “high pressure fluid” to an applicator—thus simplifies discussion,without implying the absence of natural pressure changes along path ofthe wave.

Returning to FIGS. 3a-b and 4a-b , pressure valves 90 are fluidlyconnected to the high pressure fluid source 60 and the low pressurefluid source 62, and each pressure valve 90 has an outlet 92. Eachpressure valve 90 is shiftable to a high pressure position in which thehigh pressure fluid source 60 is fluidly connected to the outlet 92 forsupplying a high pressure burst to an outlet conduit 50. Each pressurevalve 90 is also shiftable to a low pressure position in which the lowpressure fluid source 62 is fluidly connected to the outlet 92 of thepressure valve 90 for supplying a low pressure carrier wave to theoutlet conduit 50. Although not shown, each pressure valve 90 may alsobe shiftable to an “off” position in which neither the high pressurefluid source 60 nor the low pressure fluid source 62 is fluidlyconnected to the outlet 92 of the pressure valve 90. Such an alternativeconfiguration is particularly useful, for example, in embodiments wherethe device is in a parallel configuration (described below), or inembodiments that lack a vacuum valve (see discussion below) or a high orlow pressure fluid source.

In the series configuration illustrated in FIGS. 4a-b , the outlet 92 ofeach pressure valve 90 is fluidly connected to a corresponding outletconduit 50. More particularly, a tube 94 extends between and fluidlyconnects the pressure valve 90 to the corresponding vacuum valve 96. Inthe preferred embodiment, the tube 94 forms part of the internal section50 c of the outlet conduit 50 and, more preferably, a portion of therelatively rigid portion of the outlet conduit 50. Each vacuum valve 96is also fluidly connected to the vacuum source 64, and is operable toshift to a pressure or pulse position fluidly connecting the outlet 92of the pressure valve 90 to the applicator 54. In the illustratedembodiment, the vacuum valve 96 also serves to block flow of fluid fromthe pressure valve 90 when in the vacuum position, although such aconfiguration is not required (as will be described). Each vacuum valve96 is also shiftable to a vacuum position in which the vacuum pressuresource 64 is fluidly connected to the outlet conduit 50. Although notshown, each vacuum valve may optionally be shiftable to an “off”position in which no pressure source is fluidly connected to the outletconduit.

The outlet conduit preferably includes the outlet of the pressure valveand extends to the applicator, though alternative configurations such asthose discussed below may also be employed without departing from thespirit of the present invention. In the preferred illustratedembodiment, the outlet 92 begins the internal section 50 c of the outletconduit 50, and vacuum valve 96 is fluidly interposed along and formspart of the internal section 50 c. Vacuum valve 96 preferably controlsboth pressure flow from the pressure valve 90 along the outlet conduit,as well as connection of the vacuum pressure source 64 to the outletconduit.

The flow paths defined by the pressure valves and vacuum valves arepreferably of greater cross-sectional dimension than the minimum innerpassageway cross-sectional dimension of the outlet conduit, which mayhelp reduce the resistance to flow presented by the valves. Thepreferred embodiment employs fast-acting solenoid valves, preferablydirect-action valves such as the 153. Series valve sold under theHUMPHREY® trademark and operating in a DC configuration. Such valves arepreferably configured to provide a response time of less than aboutfifteen (15) milliseconds.

FIGS. 5a-b further illustrate the preferred embodiment of the presentinvention. FIG. 5a illustrates a power filter 98 for reducing electricalnoise of the power used by the device 10, a housing cooling structure100 illustrated as a fan, and an AC power inlet 102 for receipt of aplug for charging and/or powering the device. In alternativeembodiments, the device may include a battery (not shown) for poweringthe device in mobile applications in which AC power supplies are notreadily available or positioned advantageously. AC inlet 102 supplies ACpower to power supply 104 (see FIG. 5b ) and to compressor 72.Preferably, power supply 104 is a 12-volt DC power supply. Power supply104 in turn supplies power to cooling structure 100 and to valves 90,96. Power supply 104 also supplies DC power to a 5-volt DC logic powersupply (not shown) seated on an internal control board 106. The logicpower supply powers logical components of the internal control board106.

The device 10 of the preferred embodiment further includes an outletpressure sensor assembly 108 for measuring the pressure of the pulsesupplied to the associated applicator 54. The illustrated assembly 108includes a port 108 a and a pressure sensor 108 b fluidly connected tothe port 108 a. The port 108 a presents a coupling surface 108 cconfigured to flushly receive the annular lip 54 a of the applicator 54,such that the pulse delivered to the applicator 54 is communicated tothe sensor 108 b.

FIGS. 5a-b also illustrate a control system 109 including a processor orprocessing element (not shown) and a memory or memory element (notshown), each of which is seated on the internal control board 106.Though not required, in the preferred embodiment of FIG. 1a , thecontrol system 109 further includes an external second processor andmemory element (not shown) housed within computer 14. Alternativeembodiments may include additional internal and/or external processingor memory elements according to various optimizations of the device.

Each processing element may include processors, microprocessors,microcontrollers, digital signal processors (DSPs), field-programmablegate arrays (FPGAs), analog and/or digital application-specificintegrated circuits (ASICs), or the like, or combinations thereof. Eachprocessing element may generally execute, process, or run instructions,code, code segments, software, firmware, programs, applications, apps,processes, services, daemons, or the like. Each processing element mayalso include hardware components such as finite-state machines,sequential and combinational logic, and other electronic circuits thatcan perform the functions necessary for the operation of the currentinvention. Each processing element may be in communication with theother electronic components through serial or parallel links thatinclude address busses, data busses, control lines, and the like.

Each memory element may include data storage components such asread-only memory (ROM), programmable ROM, erasable programmable ROM,random-access memory (RAM) such as static RAM (SRAM) or dynamic RAM(DRAM), hard disks, floppy disks, optical disks, flash memory, thumbdrives, universal serial bus (USB) drives, or the like, or combinationsthereof. Each memory element may include, or may constitute, a“computer-readable medium”. Each memory element may store theinstructions, code, code segments, software, firmware, programs,applications, apps, services, daemons, or the like that are executed bythe processing element. Each memory element may also store settings,data, documents, sound files, photographs, movies, images, databases,and the like. Any or all of the predetermined values discussed herein,including the predetermined high pressure predetermined amount of time,the second predetermined amount of time, objectives and the frequency ofpulses may be stored in one or more memories, such as electricallyerasable read-only memories, that are accessible to one or more of theprocessing elements of the control system.

The control system 109 further includes a power on/off switch 110 seatedon the control panel 32, which controls the overall availability ofpower to the device 10, for example by permitting or cutting off powerto the power supply 104. The control system 109 also includes an allchannel data output port 112 for exporting data regarding operatingconditions and performance of all outlet conduits 50. Yet further, thecontrol system 109 preferably includes eight individual data outputports 114, one each for exporting such data regarding a single outletconduit 50. The preferred control system 109 additionally includes acommon computer port 116, such as a USB port, and an input signal port118 for receiving instructions electronically. Also, depicted in FIG. 5aare vacuum pressure regulator control knob 120 and low pressureregulator control knob 122.

The data output ports 112, 114, common computer port 116, and inputsignal port 118 are configured to provide electrical communicationbetween the control system 109 elements housed within or fixed to themobile housing 20 (described above) and an external processing elementsuch as the processing element found in the laptop computer 14illustrated in FIG. 1.

The external processing element may receive data regarding theperformance and operating conditions of the device 10, such as valveactuation times, effected pulse waveforms from outlet conduits 50,pressure of the compressible fluid at various points in the device 10,set points for controlling the various device components, and other datagathered by the control system 109 relating to device settings andperformance history. The external processing element may also beelectrically connected to sensing device 12 (see discussion above andFIG. 1) and may receive data from the sensing device 12.

In the illustrated preferred embodiment, the control system 109 iselectrically connected and sends signals to the pressure valves 90 andvacuum valves 96 to actuate them and shift their respective positions.The computer 14 preferably provides instructions to the processor of theinternal control board 106 regarding device 10 settings and operation,including with respect to valve 90, 96 actuation timing. The processorof the internal control board 106 in this embodiment issues electricalsignals to actuate the valves 90, 96 according to the computer 14instructions.

In the preferred embodiment, the processor of the computer 14 is alsoelectrically connected to the sensing device 12, and receives datatherefrom. The preferred control system 109 also optionally providesoperational instructions to the sensing device 12 and to the tactilestimulation device 10, although only control of the tactile stimulationdevice is critical in this embodiment. Moreover, in certain embodiments,the external computer is not required, and the operational instructionsfor device settings and operation may be generated and issued by theprocessing element of the internal control board.

The preferred control system 109 may generate operational instructions,which may include adjustments to high pressure, low pressure, vacuumpressure or valve actuation timing with respect to the tactilestimulation device 10, by processing data from the tactile stimulationdevice 10 and data received from the sensing device 12. Such processingmay be done further in view of at least one objective provided by anoperator and/or by code stored in memory accessible to the externalprocessing element. For example, an objective may relate to levels ofneuronal response sensed by the sensing device 12. If the desiredneuronal response is not detected following a pulse, the externalprocessing element of the computer 14 may process this data inconjunction with data regarding the operating parameters of the tactilestimulation device 10, and provide instructions to the internal controlboard 106 to adjust the operating parameters of the tactile stimulationdevice 10 in an attempt to generate pulse(s) with a greater chance offulfilling the desired objective.

In the preferred embodiment, the control system 109 is also electricallyconnected to and commands the other components of the device 10, forexample the compressor 72 to control pressure and vacuum production, thepower filter 98, and the housing cooling structure 100 to ventilate orotherwise maintain acceptable temperature within the mobile housing 20.

Returning to FIGS. 4a-b , in one mode of operation in which the device10 is in the preferred series configuration described above, the device10 starts from an initial resting state in which the vacuum valve 96 isin the vacuum position fluidly connecting the vacuum pressure source 64to the outlet conduit 50. In this resting state, the vacuum created byapplication of the vacuum pressure to the outlet conduit 50 helps tokeep the applicator 54 affixed to its application site. In addition, ithas been observed that the resulting reduced pressure at the applicator54 is advantageous in preparing the application site to receive a pulse,and may help optimize neuronal responses to pulse stimuli by creating agreater pressure differential between the resting state and a stimulatedstate than, for example, that which would be felt if the applicator 54were at ambient pressure in its resting state. The pressure valve 90 isin a high pressure position in the resting state, fluidly connecting thehigh pressure fluid source 60 to an inlet (not shown) in the vacuumvalve 96, though the vacuum valve 96 has not yet shifted to fluidlyconnect the high pressure fluid source 60 with the applicator 54.

The pressure valve 90 and vacuum valve 96 are actuated to shift betweenvalve positions by the control system 109 of the device. A pulse isinitiated by shifting the vacuum valve 96 from its resting state in thevacuum position to the pressure position, thereby substantially cuttingoff the fluid connection between the vacuum pressure source 64 and theoutlet conduit 50 and establishing a fluid connection between the highpressure fluid source 60 and the applicator 54. This generates aninitial burst supplied by the high pressure fluid source 60 at a highpressure that propagates at roughly the speed of sound toward theapplicator 54.

After a high pressure pre-determined amount of time, the pressure valve90 is shifted to the low pressure position thereby substantially cuttingoff the fluid connection between the high pressure fluid source 60 andthe outlet conduit 50 and establishing a fluid connection between thelow pressure fluid source 62 and the outlet conduit 50. The low pressurefluid source 62 supplies compressible fluid at the low pressure which inturn propagates toward the applicator 54 at roughly the speed of sound,acting as a carrier wave initially for the high pressure burst and thenas a sustained pressure wave for the pulse. After a secondpre-determined period of time, the vacuum valve 96 is shifted from thepressure position to the vacuum position to substantially cut off theconnection of the low pressure fluid source 62 with the applicator 54and return the device 10 to its resting state. These steps may berepeated for generation of additional pulses by the device 10 and forcreation of pulse patterns having a desirable frequency based on thedesired application.

In a preferred embodiment of the above configuration, the high pressurepre-determined period of time is less than about thirty (30)milliseconds, and in many cases optimally between about ten (10)milliseconds to about fifteen (15) milliseconds. The secondpre-determined period of time in a preferred embodiment is between aboutten (10) milliseconds and about ninety (90) milliseconds. Inapplications where a pattern of pulses is desired, the time betweenpulses, i.e., the time in which the device is in a resting state withvacuum pressure applied to the outlet conduit, is preferably betweenabout two-hundred (200) milliseconds and about one thousand (1000)milliseconds.

It should be noted that, in the illustrated preferred embodiment, thetube 94 connecting pressure valve 90 to vacuum valve 96 may dumpresidual high pressure compressible fluid into the low pressure fluidsource 62 following shifting of the pressure valve 90 from the highpressure position to the low pressure position. This is one of thepressure spike scenarios described above in which the low pressureregulator 76 b comprising a back pressure regulator is particularlyuseful in bleeding off such excess high pressure from the low pressurefluid source.

Reference to a high, low or vacuum pressure associated with one of theregulator outlets does not necessarily indicate the direction of flow ofcompressible fluid is away from such outlet. This is particularly truein the case of vacuum pressure or in instances of flow to the lowpressure regulator, wherein the fluid moves toward (not away) from theregulator. For example, the low pressure regulator will commonlyregulate the low pressure supplied by the pressurized fluid supply byreleasing higher pressure compressible fluid to the ambient environment(see discussion above of back pressure regulator). In these embodiments,higher pressure fluid flows toward the low pressure regulator forpartial venting to regulate the low pressure fluid, even though the lowpressure regulator is said to be “supplying” the low pressure fluid. Inanother example, where a high pressure spike occurs “downstream” in thelow pressure fluid source during operation, such as at the pressurevalve in the pressurized series configuration, fluid pressure mayactually flow from the low pressure manifold “upstream” through themanifold inlet tube and up through other components of the low pressurefluid source until the spike is vented by the low pressure regulator toreturn the low pressure fluid source to the target low pressure. Incertain embodiments, the effects of any such pressure spikes may beminimized by reducing the volume of the fluid connection between thepressure valve and vacuum valve and/or by increasing the volume of thelow pressure reservoir. In a further example, the vacuum pressure sourcenormally supplies a vacuum to the outlet conduit, thus drawingcompressible fluid flow toward the vacuum pressure regulator.

Through the series of steps outlined above, the preferred embodiment ofthe tactile stimulation device 10 generates two-stage pulses ofcompressible fluid—comprising a high pressure burst backed by a lowpressure carrier wave—directed to an application site by an applicator54. This new two-stage pulse has advantages that are desirable for awide range of medical uses, including diagnostic and therapeuticapplications. The two-stage pulse of embodiments of the presentinvention improves sluggish rise times and imprecise wave forms of priorart devices, thereby permitting creation of, for example, more“rectangular” waveforms such as those previously only realized bytactile stimulation devices relying on electrical current to carrypulses to the subject.

For example, prior art devices may employ fluid lines about fifteen (15)feet in length to carry pulses of compressible fluid from a compressorto an application site. With the prior art device, each exemplary pulsemay be initiated by turning the compressor on and concluded by turningthe compressor off, for application of a pulse of about fifty (50)milliseconds to an application site of a person. Typical stimulus risetimes—defined as the time it takes for the stimulus to progress from tenpercent (10%) to ninety percent (90%) of its peak intended amplitude—areconsidered very rapid in prior art devices at around twenty-five (25)milliseconds. Given that an exemplary pulse lasts for around fifty (50)milliseconds, the pulse of prior art devices is commonly delivered in arelatively parabolic waveform at the application site near the skin.

By employing the two-stage pulse of the preferred embodiment of thepresent invention, shorter rise times are achievable, such that thelargely parabolic pulse waveforms of existing devices may be replacedwith more “rectangular” waveforms. In many cases, this permits much moreof the duration of each pulse to be held at the desired pulse pressureor stimulus amplitude rather than, for example, merely being applied atthe peak of a parabolic waveform pulse. The device 10 supplies betterwaveforms while also providing a relatively cheap solution that does notrequire positioning of pressure sources that are likely to interferewith sensory equipment operation.

Further, the waveform produced by the device 10 may be observed, and thedevice may be tuned for each individual outlet conduit in considerationof the application and objectives being sought after. This also permitsoptimization for each unique outlet conduit in view of possible varianceof physical properties and imperfections that may be or become apparentfrom one conduit/valve passage to the next. Exemplary imperfections mayinclude small variations in actuation timing between valves and thelike.

For example, as described elsewhere herein “rectangular” waveforms arepreferred for certain applications such as in diagnostic somatosensorytesting, and it has been observed that a rise time of fifteen (15)milliseconds or less may be advantageous in such applications. Anoperator of the device 10 may tune each outlet conduit 50 individuallyaccording to these exemplary objectives by first coupling the applicator54 to the port 108 a at the control panel 32. The operator may theninitiate generation of a pulse according to the description above, andrecord the resulting waveform via output of the sensor 108 b. If therise time is seventeen (17) milliseconds, for example, the operator maywish to increase the high pressure pre-determined period of time todecrease rise time. Such an adjustment, may, however, also increase“overshoot”—the front part of a pulse waveform that exceeds the targetpulse pressure before falling back to the desired pressure. Othervariables that may be useful for tuning include high pressure, lowpressure, and, in more experimental settings, outlet conduit length andinner diameter, tube bore smoothness, applicator dimensions, and thelike.

By way of more specific example, where predetermined periods of time aremeasured to properly coordinate pulses and pulse stages, in a preferredembodiment, time measuring commences upon the shifting of a valveposition, and more particularly when the corresponding actuation signalis issued by the control system 109. However, actuation times may varyacross valves. Thus, to achieve a pressure flow of a desired duration,it may be necessary to perform additional tuning to account for any suchinconsistencies. An example based on the device 10 of the preferredembodiment may comprise the following sequence of events: (a) sendelectrical signal for actuation of the vacuum valve 96 to the pressureposition, commencing the high pressure pre-determined amount of time,(b) after passage of the high pressure pre-determined amount of time,for example fifteen (15) milliseconds, send electrical signal foractuation of the pressure valve 90 to the low pressure position,commencing the second pre-determined period of time, and (c) afterpassage of the second pre-determined period of time, for examplethirty-five (35) milliseconds, send electrical signal for actuation ofthe vacuum valve 96 to the vacuum position, returning the device 10 tothe resting state. If, following this sequence and measurement of theresulting pulse by the outlet pressure sensor assembly 108, it isdetermined that either of the high pressure burst or low pressurecarrier wave does not achieve the duration expected had the valvesperformed their positional shifts in substantially the same amount oftime, the device may be tuned by adjusting the timing commanded by thecontrol system 109 to achieve the desired waveform and characteristics.

Individual tuning and the ability to actuate pulses independently alongseparate outlet conduits permits patterns of pulses to be fashioned, forexample to simulate stroking touches or the like. The embodiment of FIG.1a illustrates such a pattern arrangement. The eight outlet conduits 50extend toward the subject in two groups of four, with one group appliedto the left arm and the other to the right arm in linear applicationsite patterns. Exemplary pulse patterns that may be supplied to theapplicators 54 of each group in this arrangement include a strokingpattern simulated by applying a pulse to each of the four applicators 54in a closely-timed successive series. More specifically, a pulse may bedelivered to a first applicator 54 of the left arm group, a second pulsemay be delivered just after the first pulse to the next applicator 54 inthe illustrated linear configuration, followed in quick succession by apulse each for the third and fourth applicators 54. This pattern resultsin simulation of a stroking motion quickly moving up the left arm fromthe first applicator 54 to the fourth applicator 54. A similar patternmay be applied simultaneously or with staggered timing by the right armgroup of applicators 54. It is envisioned that other application sitepatterns, pulse patterns, and pulse frequencies may be employed withembodiments of the device of the present invention without departingfrom its spirit.

Though the pressure sensor port is preferably mounted on the controlpanel, it is also foreseen that tuning may be achieved by a variety ofother means such as by including an applicator pressure sensor at eachapplicator and by optionally providing a feedback loop from eachapplicator pressure sensor to a processor that analyzes the feedbackdata and automatically adjusts system settings according to a waveformoptimization objective such as the desired rise time and maximumovershoot definition.

The present invention provides advantages over the prior art, includingthat it provides improved tactile stimulation using a pneumatic devicefor delivering pulses of compressible fluid over a distance so thatsluggish rise time, imprecise waveforms and other disadvantages ofexisting pneumatic tactile stimulation devices can be minimized. In oneimplementation, the present invention accomplishes this with a lesscomplex and less expensive solution that does not, for example, requirepositioning of pressure sources that are likely to interfere withsensory equipment operation.

As discussed above, the outlet conduit preferably includes the outlet ofthe pressure valve and extends to the applicator, and includes a vacuumvalve. However, alternative configurations may also be employed withoutdeparting from the spirit of the present invention. In anotherembodiment illustrated in FIG. 6, the pressure valve 200 has an outlet202 fluidly connected to the applicator 204, and the vacuum valve 206 isnot fluidly interposed there between. The vacuum valve 206 in thisconfiguration is fluidly connected to the outlet conduit 208 to supplyvacuum pressure thereto, for example at a t-connection with the outletconduit 208. In this parallel configuration, pressure valve 200 andvacuum valve 206 are preferably shiftable to an “off” position. In theillustrated embodiment, pressure valve 200 is shown as a three positionvalve, which is an exemplary mechanism for providing the “off”functionality for the pressure valve 200.

In the resting state of the parallel configuration illustrated in FIG.6, the pressure valve 200 is in its “off” position as described aboveand the vacuum valve 206 is in its vacuum position fluidly connectingthe vacuum source 210 to the outlet conduit 208. A pulse is initiatedfor the applicator 204 by shifting the vacuum valve 206 from its restingstate in vacuum position to its “off” position, thereby substantiallycutting off the fluid connection between the vacuum pressure source 210and the outlet conduit 208. As closely thereafter as possible, orsimultaneously, the pressure valve 200 is shifted to the high pressureposition, thereby establishing a fluid connection between the highpressure fluid source 212 and the outlet conduit 208. This generates aninitial burst supplied by the high pressure fluid source 212 at a highpressure that propagates at roughly the speed of sound toward theapplicator 204.

After a high pressure pre-determined amount of time, the pressure valve200 is shifted to the low pressure position thereby substantiallycutting of the fluid connection between the high pressure fluid source212 and the outlet conduit 208 and establishing a fluid connectionbetween the low pressure fluid source 214 and the outlet conduit 208.The low pressure fluid source 214 supplies compressible fluid at the lowpressure which in turn propagates toward the applicator 204 at roughlythe speed of sound, acting as a carrier wave initially for the highpressure burst and then as a sustained pressure wave for the pulse.After a second pre-determined period of time, the pressure valve 200 isshifted back to the “off” position to substantially cut off the fluidconnection between the low pressure fluid source 214 and the outletconduit 208. The vacuum valve 206 is shifted as soon thereafter aspossible, or simultaneously, from the “off” position to the vacuumposition to return the device to its resting state.

In a preferred embodiment of the above parallel configuration, the highpressure pre-determined period of time is between about ten (10)milliseconds and about thirty (30) milliseconds, and in many casesoptimally between about ten (10) milliseconds to about fifteen (15)milliseconds. The second pre-determined period of time in a preferredembodiment is between about ten (10) milliseconds and about ninety (90)milliseconds. In applications where a pattern of pulses is desired, thetime between pulses, i.e., the time in which the device is in a restingstate with vacuum pressure applied to the outlet conduit, of a preferredembodiment is between about two hundred (200) milliseconds and about onethousand (1000) milliseconds.

It should be noted, for example with respect to the three position valve200 illustrated in FIG. 6, that a multi-position valve described hereinmay be replaced with a plurality of valves connected in parallel,without departing from the spirit of the present invention.

In a third embodiment of the present invention (not shown), the vacuumvalve may be removed from the outlet conduit. In the resting state ofthis third embodiment, the pressure valve is in its “off” position. Apulse is initiated for the outlet conduit by shifting the pressure valvefrom its “off” position to the high pressure position therebyestablishing a fluid connection between the high pressure fluid sourceand the outlet conduit. This generates an initial burst supplied by thehigh pressure fluid source at a high pressure that propagates at roughlythe speed of sound toward the applicator. After a high pressurepre-determined amount of time, the pressure valve is shifted to the lowpressure position thereby substantially cutting of the fluid connectionbetween the high pressure fluid source and the outlet conduit andestablishing a fluid connection between the low pressure fluid sourceand the outlet conduit. The low pressure fluid source suppliescompressible fluid at the low pressure which in turn propagates towardthe applicator at roughly the speed of sound, acting as a carrier waveinitially for the high pressure burst and then as a sustained pressurewave for the pulse. After a second pre-determined period of time, thepressure valve is shifted back to the “off” position to substantiallycut off the fluid connection between the low pressure fluid source andthe outlet conduit.

In a fourth embodiment of the present invention (not shown), the vacuumvalve is fluidly connected to a pressure source as well as to the vacuumsource. In one embodiment, this may be accomplished by removing the tube94 illustrated as running between pressure valve and the vacuum valve inFIG. 3a from the outlet 92 of the pressure valve 90 and fluidlyconnecting it directly to one of the manifolds 20 d and 30 f. In thisfourth embodiment, the outlet conduit extends from the vacuum valveoutlet to the applicator. The vacuum valve is shiftable between apressure position fluidly connecting such pressure fluid source to theapplicator, and a vacuum position fluidly connecting the vacuum pressuresource to applicator. A pulse is initiated by shifting from the vacuumposition to the pressure position for a pressure pre-determined periodof time, and is concluded by shifting back to the vacuum position.Preferably, in this fourth embodiment the pressure pre-determined periodof time is between about forty (40) milliseconds and about one hundred(100) milliseconds. In applications where a pattern of pulses isdesired, the time between pulses, i.e., the time in which the device isin a resting state with vacuum pressure applied to the outlet conduit,of a preferred embodiment is between about two-hundred (200)milliseconds and about one thousand (1000) milliseconds.

Although the above description presents features of preferredembodiments of the present invention, other preferred embodiments mayalso be created in keeping with the principles of the invention.Furthermore, these other preferred embodiments may in some instances berealized through a combination of features compatible for use togetherdespite having been presented independently in the above description.

The preferred forms of the invention described above are to be used asillustration only and should not be utilized in a limiting sense ininterpreting the scope of the present invention. Obvious modificationsto the exemplary embodiments, as hereinabove set forth, could be readilymade by those skilled in the art without departing from the spirit ofthe present invention.

For the avoidance of doubt, reference to “each” component, for exampleto “each valve,” in describing the exemplary embodiments disclosedherein does not imply a requirement that a certain minimum number ofoutlet conduits or valves be included in the present invention otherthan as expressly stated in any claims, nor that each outletconduit/valve pair of a device according to an embodiment of the presentinvention must operate in the same configuration as others.

The inventors hereby state their intent to rely on the Doctrine ofEquivalents to determine and assess the reasonably fair scope of thepresent invention as pertains to any apparatus not materially departingfrom but outside the literal scope of the invention set forth in thefollowing claims.

What is claimed is:
 1. A device for providing tactile stimulation via apulse of compressible fluid, said tactile stimulation device comprising:a pressurized fluid source operable to generate the pulse ofcompressible fluid; a vacuum pressure source; an outlet conduit beingfluidly coupled to the sources and including an applicator configured todirect the pulse against the skin of a subject; and a vacuum valveshiftable between a vacuum position, in which the vacuum pressure sourceis fluidly connected to the outlet conduit, and a pulse position, inwhich the vacuum pressure source is not fluidly connected to the outletconduit, with the vacuum valve shifting from the vacuum position to thepulse position to permit the pulse of compressible fluid to propagatetoward the applicator.
 2. The tactile stimulation device as claimed inclaim 1, further comprising: a control system operably coupled to thevacuum valve to control shifting of the vacuum valve between the vacuumand pulse positions.
 3. The tactile stimulation device as claimed inclaim 2, further comprising: an outlet pressure sensor connectable tothe applicator to sense a pressure associated with the pulse supplied tothe applicator, said outlet pressure sensor being operably coupled withthe control system.
 4. The tactile stimulation device as claimed inclaim 2, further comprising: a data link coupled to the control systemand being connectable to a neuronal sensing device.
 5. The tactilestimulation device as claimed in claim 2, said control system beingoperable to initially position the vacuum valve in the vacuum positionwhile fluid flow from the pressurized fluid source is blocked, and thenshift the vacuum valve to the pulse position.
 6. The tactile stimulationdevice as claimed in claim 5, said vacuum valve being fluidly interposedalong the outlet conduit between the pressurized fluid source and theapplicator, said vacuum valve fluidly connecting the pressure fluidsource to the applicator when in the pulse position, said vacuum valveblocking fluid flow from the pressurized fluid source when in the vacuumposition.
 7. The tactile stimulation device as claimed in claim 6, saidcontrol system being operable to return the vacuum valve back to thevacuum position after a second predetermined amount of time.
 8. Thetactile stimulation device as claimed in claim 6, said outlet conduitdefining an inner conduit flow passageway having a minimum passagewaycross-sectional dimension, said vacuum valve defining an inner valveflow path having a minimum path cross-sectional dimension that isgreater than the passageway cross-sectional dimension.
 9. The tactilestimulation device as claimed in claim 8, said minimum passagewaycross-sectional dimension being between about 0.002 square inches andabout 0.05 square inches.
 10. The tactile stimulation device as claimedin claim 1, said vacuum pressure source being operable to supply avacuum between about −1 psi and about −2 psi.
 11. The tactilestimulation device as claimed in claim 1, said vacuum valve being afast-acting solenoid valve configured to complete shifting between thevacuum and pulse positions in less than about 15 milliseconds.
 12. Thetactile stimulation device as claimed in claim 1, said outlet conduitincluding proximal and distal sections, with the proximal sectionextending from the pressurized fluid source and the distal section beingadjacent the applicator, said distal section being more flexible thanthe proximal section.
 13. The tactile stimulation device as claimed inclaim 1, further comprising: a mobile housing in which the sources andthe vacuum valve are located, said outlet conduit extending from themobile housing to the subject.
 14. The tactile stimulation device asclaimed in claim 13, said outlet conduit presenting a length betweenabout 3 feet and 30 feet, with at least a majority of the length of theoutlet conduit being external to the mobile housing.
 15. The tactilestimulation device as claimed in claim 1, said outlet conduit beingformed of magnetically unresponsive materials.
 16. A method of providingtactile stimulation via a pulse of compressible fluid delivered to anapplicator, said tactile stimulation method comprising the steps of: (a)supplying a high pressure compressible fluid toward the applicator; and(b) after passage of a first predetermined amount of time, switching theflow of high pressure fluid to a flow of low pressure compressible fluidtoward the first applicator, wherein the high pressure fluid flows forless time than the low pressure fluid to thereby generate the pulse ofcompressible fluid to the first applicator.
 17. The tactile stimulationmethod as claimed in claim 16, step (b) including the step of shifting apressure valve from a high pressure position, in which a high pressurefluid source is fluidly connected to the applicator, to a lower pressureposition, in which a low pressure fluid source is fluidly connected tothe applicator.
 18. The tactile stimulation method as claimed in claim17, further comprising the step of: (c) providing data regardingoperation of the pressure valve to a neuronal sensing device.
 19. Thetactile stimulation method as claimed in claim 17, said step of shiftingthe valve being performed in less than about 15 milliseconds.
 20. Thetactile stimulation method as claimed in claim 16, said firstpredetermined amount of time being less than about 30 milliseconds. 21.The tactile stimulation method as claimed in claim 20, said firstpredetermined amount of time being between about 10 milliseconds andabout 15 milliseconds.
 22. The tactile stimulation method as claimed inclaim 16, said flow of high pressure fluid and flow of low pressurebeing supplied to the applicator through an outlet conduit; and (c)supplying vacuum pressure to the outlet conduit.
 23. The tactilestimulation method as claimed in claim 22, step (c) including the stepof shifting a vacuum valve from a pulse position, in which the vacuumpressure is not fluidly connected to the outlet conduit, to a vacuumposition, in which the vacuum pressure is fluidly connected to theoutlet conduit.
 24. The tactile stimulation method as claimed in claim22, said high pressure fluid flow being at a pressure between about 6psi and about 10 psi, said low pressure fluid flow being at a pressurebetween about 1 psi and about 2 psi, said vacuum pressure being at apressure between about −1 psi and about −2 psi.
 25. The tactilestimulation method as claimed in claim 22, further comprising, (d)blocking high and low pressure fluid flow along the conduit during step(c).
 26. The tactile stimulation method as claimed in claim 25, step (c)being performed prior to steps (a) and (b).
 27. The tactile stimulationmethod as claimed in claim 26, step (c) not occurring during steps (a)and (b).
 28. The tactile stimulation method as claimed in claim 27, step(c) including the step of shifting a vacuum valve from a pulse position,in which the vacuum pressure is not fluidly connected to the outletconduit, to a vacuum position, in which the vacuum pressure is fluidlyconnected to the outlet conduit, said vacuum valve being fluidlyinterposed along the outlet conduit upstream from the applicator, saidvacuum valve permitting high and low pressure fluid flow to theapplicator when in the pulse position, said vacuum valve blocking highand low pressure fluid flow to the applicator when in the vacuumposition.
 29. The tactile stimulation method as claimed in claim 28,further comprising the step of: (e) returning the vacuum valve to thevacuum position after a second predetermined amount of time, with thesecond predetermined amount of time commencing once the firstpredetermined amount of time expires.
 30. The tactile stimulation methodas claimed in claim 29, said first predetermined amount of time beingless than about 30 milliseconds, said second predetermined amount oftime being between about 10 milliseconds and about 90 milliseconds. 31.The tactile stimulation method as claimed in claim 16, furthercomprising the steps of: (c) applying multiple applicators in discretelocations on the subject; and (d) repeating steps (a) and (b) for eachof the applicators.